LaserDisc

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LaserDisc (abbreviated LD ) is the first commercially licensed home video format and media storage media disk, sold and marketed as a MCA DiscoVision in the United States in 1978.

Although this format is able to offer higher quality video and audio than its consumer competitors, VHS and Betamax, LaserDisc has never been successfully used extensively in North America, in large part due to the high cost for the player and the video title itself and the inability to record TV programs. It was not a popular format in Europe and Australia when it was first released, but eventually gained traction in the region to become popular in the 1990s.

By contrast, the format is much more popular in Japan and in the more affluent areas of Southeast Asia, such as Hong Kong, Singapore and Malaysia, and is a rental video media that was prevalent in Hong Kong during the 1990s. Superior video and audio quality makes it a popular choice among video and movie fans throughout their lifetime. The technologies and concepts behind LaserDisc are the basis for optical disc format then including Compact Disc (CD), DVD and Blu-ray (BD).

Video LaserDisc

Histori

Optical video recording technology, using transparent discs, was created by David Paul Gregg and James Russell in 1958 (and patented in 1961 and 1990). Patent Gregg was purchased by MCA in 1968. In 1969, Philips has developed videodisc in a reflective mode, which has advantages over transparent mode. MCA and Philips then decided to combine their efforts and first openly demonstrate the video disc in 1972.

LaserDisc was first available in the market, in Atlanta, Georgia, on December 15, 1978, two years after the introduction of VHS VCR, and four years before the introduction of the CD (based on laser disc technology). Initially licensed, sold, and marketed as MCA DiscoVision (also known as " DiscoVision ") in North America in 1978, Optical Videodisc Systems , Videodisc Reflective Optics, Laser Optical Videodisc , and Disco-Vision (with hyphen), with the first the player refers to the format as " Long Play Video ".

Pioneer Electronics then purchased a majority stake in the format and marketed it as LaserVision (name of the format) and LaserDisc (brand name) in 1980, with some unofficial releases referring to being as " Laser Videodisc ". Philips produces players while MCAs produce discs. The Philips-MCA partnership did not work, and was terminated after several years. Some scientists responsible for initial research (Richard Wilkinson, Ray Dakin and John Winslow) founded Optical Disc Corporation (now ODC Nimbus).

In 1979, the Museum of Science and Industry in Chicago opened a "Newspaper" exhibit that uses interactive LaserDiscs to allow visitors to search the front page of the Chicago Tribune newspaper. This is an early example of public access to information stored electronically in the museum.

In 1984, Sony introduced the LaserDisc format that can store all forms of digital data, as a data storage device similar to a CD-ROM, with a huge capacity of 3.28 GiB, comparable to the next DVD-ROM format.

The first LaserDisc title to be marketed in North America was the release of the MCA DiscoVision from Jaws in 1978. The last title released in North America was Paramount's Bringing Out the Dead in 2000. Last The film released by Japan is the Hong Kong film Tokyo Raiders from Golden Harvest. A dozen more titles continued to be released in Japan, until the end of 2001. The production of LaserDisc players continued until January 14, 2009, when Pioneer stopped making it.

Estimated in 1998, LaserDisc players were in about 2% of US households (about two million). By comparison, in 1999, players were in 10% of Japanese households. LaserDisc was released on June 10, 1981 in Japan, and a total of 3.6 million LaserDisc players were sold there. A total of 16.8 million LaserDisc players were sold worldwide, of which 9.5 million were sold by Pioneer.

In the early 2000s, LaserDisc was completely replaced by DVDs in the North American retail market, as both players and software were then produced. Players are still exported to North America from Japan until the end of 2001. This format has retained some popularity among American collectors, and to a greater extent in Japan, where the format is better supported and more common throughout its life. In Europe, LaserDisc has always been an unclear format. It was chosen by the British Broadcasting Corporation (BBC) for the BBC Domesday Project in the mid-1980s, a school-based project to commemorate 900 years since the original Domesday Book in the UK. From 1991 to early 2000s, the BBC also used LaserDisc technology to play channel idents.

Maps LaserDisc

Design

LaserDisc standard home video is 30 cm (12 inches) in diameter and consists of two one-sided aluminum-plated discs. Despite appearing similar to compact discs or DVDs, LaserDiscs uses analog video stored in a composite domain (has video bandwidth of approximately equivalent to the 1-inch (25-mm) VTR Type format) with analog stereo FM sound and PCM digital audio. LaserDisc on the most basic level is still recorded as a series of holes and ground like CD, DVD, and even Blu-ray Disc at this time. However, while encoding is a binary property, the information is encoded as an analog pulse-width modulation with a 50% duty cycle, in which the information is contained in the length and spacing of the pit. In actual digital media, holes, or edges, directly represent the 1s and 0s of the binary digital information stream. Initial LaserDiscs shown in 1978 were completely analog but the format evolved to incorporate digital stereo sound in CD format (sometimes with TOSlink or coax output to feed the external DAC), and then multi-channel formats such as Dolby Digital and DTS.

Because digital encoding and compression schemes were not available or not practical in 1978, three coding formats based on rotation speeds were used:

CAV

Constant corner speed or Standard Play Disk supports some unique features like silent frame, variable slow motion, and vice versa. CAV disks are rotated at constant rotational speeds (1800 rpm for 525 lines and 1500 rpm for 625 line discs) during playback, with one video frame read per revolution. In this mode, 54,000 individual frames (30 minutes of audio/video for NTSC, 36 minutes for PAL) can be stored on one side of the CAV disc. Another unique attribute for CAV is to reduce the visibility of the crosstalk from adjacent tracks, because in CAV, each crosstalk at a certain point in the frame is only from the same point in the next or previous frame. CAV is used less frequently than CLV, and is provided for special edition feature films to highlight bonus material and special effects. One of the most interesting advantages of this format is the ability to reference each frame of the movie directly with numbers, features that are exciting specifically for movie fans, students and others attracted by error studies in staging, continuity and so on./dd>

CLV

Constant linear velocity or disk Play Extension does not have the CAV "trick" trick feature, offers only simple playback on all top-class LaserDisc players that combine digital frame storage. This high-end LaserDisc player can add features that are not normally available for CLV disks such as forward and backward variables, and "pauses" like VCRs. By gradually slowing down their rotational speed (1,800-600 rpm) CLV encoded discs can store 60 minutes of audio/video per side for NTSC (64 minutes for PAL), or two hours per disk. For movies with run-time of less than 120 minutes, this means they can fit on one disc, lower the cost of the title and eliminate the annoying "wake up to change disk" exercise, at least for those who have dual bodied players. Most titles are only available in the CLV (some partially released titles of CLV, some CAV.For example, a 140 minute movie can fit on either side of the CLV and one side of CAV, making it possible for CAV-only features during the climax of the movie).

CAA

In the early 1980s, due to problems with crosstalk distortion in the extended CLV playing LaserDiscs, Pioneer Video introduced a constant angular acceleration (CAA) format for extended rotary discs. CAA is very similar to CLV, except for the fact that CAA varies the disk angle rotation in a controlled step rather than gradually slowing down with a stable linear velocity when the CLV disk is read. With the exception of 3M/Imation, all LaserDisc manufacturers adopt the CAA coding scheme, although the term is rarely (if ever) used on consumer packaging. CAA encoding improves image quality and greatly reduces crosstalk and other tracking issues when fully compatible with existing players.

When Pioneer introduced digital audio to LaserDisc in 1985, it further refined the CAA format. CAA55 was introduced in 1985 with a total playback capacity per side 55 minutes 5 seconds, reducing video capacity to resolve bandwidth issues with the inclusion of digital audio. Some titles released between 1985 and 1987 are analogue audio just because of the title length and the desire to save movies on one disk (for example, Back to the Future ). In 1987, Pioneer had overcome technical challenges and was able to once again encode the CAA60, allowing a total of 60 minutes 5 seconds. Pioneer further refined the CAA, offering CAA45, 45 minute material encoding, but filling the entire playback surface. Used only on some titles, CAA65 offers 65 minutes 5 seconds of playback time per side. There are some titles pressed by Technidisc that use CAA50. The last variant of CAA is CAA70, which can accommodate 70 minutes of playback time per side. There is no known use of this format in the consumer market.

Audio

Sound can be stored in analog or digital format and in various surround sound formats; NTSC disks can carry two analog audio tracks, plus two uncompressed PCM audio tracks, which (EFM, CIRC, 16-bit and 44,056 kHz frequencies). PAL disks can carry a single pair of audio tracks, either analog or digital and the digital tracks on the PAL disk are 16-bit 44.1 kHz as on CDs; in the UK, the term "LaserVision" is used to refer to disks with analog sound, while "LaserDisc" is used for those with digital audio. Digital sound signals in both EFM encoded formats such as on CD. Dolby Digital (also called AC-3) and DTS - which are now common in DVD titles - were first available in LaserDisc, and Star Wars: Episode I - The Phantom Menace (1999) released at LaserDisc in Japan, is one of the first home video releases to ever include a 6.1 channel Dolby Digital EX Surround. Unlike DVDs, which carry Dolby Digital audio in digital form, Dolby Digital's LaserDiscs store in the form of frequency modulation in tracks commonly used for analog audio. Dolby Digital extraction from LaserDisc requires players equipped with special "AC-3 RF" output and external demodulator in addition to an AC-3 decoder. The demodulator was required to convert 2.88 MHz AC-3 modulation information on disk into 384 kbit/s signal that the decoder could handle. DTS audio, when available on disk, replaces digital audio tracks; hear DTS sound requires only S/PDIF compatible digital connection to DTS decoder.

In the mid to late 1990s many high-end AV receivers included a special demodulator circuit for the players of LaserDisc RF modulated Dolby Digital AC-3 signals. In the late 1990s with LaserDisc players and disc sales declining due to the increasing popularity of DVDs, AV receiver manufacturers removed demodulator circuits. Although the DVD player is capable of playing Dolby Digital tracks, the signal from the DVD player is not modulated and is not compatible with inputs designed for LaserDisc AC-3. The outboard demodulator is available for the period that converts the AC-3 signal into a standard Dolby Digital standard that is compatible with standard Dolby Digital/PCM inputs on a capable AV receiver. Another type marketed by Onkyo and others converts the AC-3 RF signal into a 6-channel analogue audio.

Two FM audio channels occupy the disk spectrum at 2.3 and 2.8 MHz on NTSC formatted disks and each channel has a 100 kHz FM deviation. FM audio carrier frequencies are chosen to minimize their visibility in video images, so even with less-controlled disks, the audio bearer in the video will be at least -35 dB down, and thus, invisible. Because of the frequency selected, the 2.8 MHz audio carrier (Right Channel) and the lower edge of the chroma signal are very close together and if the filter is not carefully regulated during mastery, interference may occur between the two. In addition, high levels of audio combined with high chroma levels can cause reciprocal interference, which causes taps to be visible in the highly saturated areas of the image. To help overcome this, Pioneer decided to implement the Noise CX Reduction System on analogue tracks. By reducing the dynamic range and peak levels of the audio signals stored on the disk, the filtering requirements are relaxed and the taps that appear to be greatly reduced or eliminated. The CX system gives a total effect of NR 20 dB, but for the sake of better compatibility for non-decoded playback, Pioneer reduces this to only a 14dB noise reduction (RCA CED system using the original 20 dB "CX" system). It also reduces the calibration tolerance of the player and helps reduce sound pumping if the CX decoder is not calibrated properly.

At least where digital audio tracks are concerned, voice quality is unmatched at that time compared to consumer videocassettes, but the quality of analog soundtracks varies greatly depending on the disk and, occasionally, players. Many early and lower LD players have poor analog audio components, and in turn many of the early discs are lacking in analog audio tracks, making digital soundtracks of any kind desired for serious fans. Early DiscoVision and LaserDisc titles do not have digital audio options, but many of those films receive digital sounds in later re-issues by Universal, and the quality of analogue audio tracks generally gets much better as time passes. Many discs originally carrying old analog stereo tracks accept Dolby Stereo and Dolby Surround new tracks instead, often in addition to digital tracks, help improve sound quality. Then the analog disks also implement CX noise reduction, which increases the ratio of their audio-noise signals.

On a DTS disk, digital PCM audio is not available, so if the DTS decoder is also unavailable, the only option is to backtrack to an analog Dolby Surround or stereo audio track. In some cases, further analog audio tracks are not available through replacements with additional audio such as isolated scores or audio commentary. This effectively reduces the playback of DTS disks on systems not equipped with DTS for mono audio, or in some cases, no movie soundtracks at all.

Only one 5.1 surround sound option exists in a particular LaserDisc (Dolby Digital or DTS), so if the surround sound is desired, the disc should be matched to the playback equipment capability (the LD player and the receiver/decoder) by the buyer. A fully equipped LaserDisc playback system that includes a newer LaserDisc player that can play digital tracks, has digital optical output for PCM audio and digital DTS, knows AC-3 audio tracks, and has AC-3 coaxial output; an external and internal AC-3 RF demodulator and AC-3 decoder; and DTS decoder. Many A/V receivers in 1990 incorporated the AC-3 decoder and DTS decoder logic, but the integrated AC-3 demodulator was rarely good inside the LaserDisc device and in the next A/V receiver.

PAL LaserDiscs has a slightly longer play time than NTSC disks, but has fewer audio options. PAL disks have only two audio tracks, consisting of only two analog tracks on the old LD PAL, or two digital only tracks on the newer disks. In comparison, NTSC LDs are then able to carry four tracks (two analog and two digital). In certain releases, one analog track is used to carry a modulated AC-3 signal for 5.1 channel audio (for decoding and playback by a new LD player with "AC-3 RF" output). However, the NTSC LD made before 1984 (like the original DiscoVision disc) only has two analog audio tracks.

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player LaserDisc

The earliest players used a helium-neon gas laser tube to read the disc and had a red-orange light with a wavelength of 632.8 m, while solid-state players used an infrared semiconductor laser diode with a wavelength of 780 nm.

In March 1984, Pioneer introduced the first consumer player with a solid-state laser, the LD-700. It was also the first LD player to load from the front and not top. One year earlier Hitachi introduced expensive industrial players with laser diodes, but players, who had poor image quality due to inadequate dropout compensators, were made only in limited quantities. After Pioneer released the LD-700, gas lasers were no longer in use with consumers, despite their profits, although Philips continued to use gas lasers in their industrial units until 1985.

Most LaserDisc players require users to manually play the disc upwards to play the other side. A number of players (all laser-based diodes) are created that are capable of playing both sides of the disc automatically.

Pioneer produces several multi-disk models that store more than 50 LaserDiscs. One company offered, for a short time in 1984, a "LaserStack" unit that added multi-disc capabilities to existing players: Pioneer LD-600, LD-1100 or Sylvania/Magnavox clones. This requires the user to physically remove the player cap for installation and attached to the top of the player. LaserStack holds up to 10 disks and can automatically load or remove them from the player or change the sides in about 15 seconds.

The first mass-produced industrial laser player was the MCA DiscoVision PR-7820, then recruited Pioneer PR7820. In North America, the unit was used at many General Motors dealerships as a source of training videos and presentations of GM's new line of cars and trucks in the late 1970s and early 1980s.

Most players made after the mid-1980s were also able to play Compact Discs. This player includes 4.7 in (12 cm) indented in the loading tray, where the CD is placed for playback. At least two Pioneer models (CLD-M301 and CLD-M90) also operate as CD changers, with some 4.7 in the indentation around the circumference of the main tray.

The Pioneer DVL-9, introduced in 1996, was Pioneer's first consumer DVD player and the first DVD/LD player combination.

The first high-definition video player is Pioneer HLD-X0. The next model, HLD-X9, features superior comb filters, and laser diodes on both sides of the disc.

Famous player

• Pioneer PR7820, the industry's first LaserDisc player, capable of being controlled by external computers, was used in the first US LaserDisc arcade game Dragon Lair.
• Pioneer CLD-1010, the first player to play 5-inch (130 mm) CD-Video discs. Released in 1987.
• Pioneer CLD-D703, 1994 model with digital audio playback.
Pioneer CLD-A100 and NEC PCE-LD1 provide the ability to play video games Sega Genesis (Mega Drive) and TurboGrafx16 (PC Engine) when used in conjunction with additional components.
• The Pioneer DVL series, capable of playing LaserDiscs and DVDs

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Branding

During its development, MCAs, which belong together with technology, call it the Optical Videodisc System , "Videodisc Optical Reflective" or "Laser Optical Videodisc", depending on the document; renamed once in 1969 to Disco-Vision and then back in 1978 to DiscoVision (without hyphens), which became official spelling. The technical documents and brochures produced by the Disco-Vision MCA during the early and mid-70s also used the term "Disco-Vision Records" to refer to a pressed disc. The MCA has the rights to catalog the world's largest films during this time, and they create and distribute the DiscoVision releases of these films under the "MCA DiscoVision" software and manufacturing labels; consumer sales of the titles began on December 15, 1978, with the Jaws .

Philips' preferred name for the format is "VLP", after the Dutch words Video Langspeel-Plaat ("Long-play disc"), which in English-speaking countries stands for Long-Play Videos. The first consumer player, the Magnavox VH-8000 even has a VLP logo on the player. For a while in the early and mid-1970s, Philips also discussed a compatible audio-only format they called "ALP", but it was quickly dropped because the Compact Disc system became an incompatible project in the Philips company. Until early 1980, the format did not have an "official" name. The LaserVision Association, comprised of MCA, Universal-Pioneer, IBM, and Philips/Magnavox, was formed to standardize the format technical specifications (which have caused problems for the consumer market) and finally labeled the system officially "LaserVision".

After its introduction in Japan in 1981, the format was introduced in Europe in 1983 under the name LaserVision although Philips used "VLP" in model designations, such as the VLP-600. Philips tried to change the name of the entire format in 1987 to "CD-Video", and while the name and logo appeared on players and labels for years, the 'official' name of the LaserVision fixed format. In the early 1990s, the format name was eventually converted to LaserDisc.

Pioneer

Pioneer Electronics also entered the optical disc market in 1977 as a 50/50 joint venture with a MCA called Universal-Pioneer and manufacturing industry players designed by MCA under the name MCA DiscoVision (PR-7800 and PR-7820). For the 1980 launch of the first Universal-Pioneer player, VP-1000 was listed as a "laser disc player", although the "LaserDisc" logo is clearly displayed on the device. In 1981, "LaserDisc" was used exclusively for the media itself, although its official name was "LaserVision" (as seen early in many LaserDisc releases just before the start of the film). However, as Pioneer reminded many video and store magazines in 1984, LaserDisc is a trademarked word, standing only for LaserVision products manufactured for sale by Pioneer Video or Pioneer Electronics. Ray Charles's 1984 commercial for LD-700 players gave birth to the term "pioneer LaserDisc" brand videodisc player. From 1981 to early 1990s, all properly licensed discs carry the LaserVision name and logo, even the title of Pioneer Artist.

On the one hand LaserDiscs controlled by Pioneer, playing the wrong side will cause the still screen to appear with a happy and upside turtle that has LaserDisc for the stomach (dubbed "LaserDisc Turtle"). The words "Program material recorded on the other side of this disc" are under the tortoise. Other manufacturers use plain text messages without graphics.

MCA

During the early years, MCA also produced discs for other companies including Paramount, Disney and Warner Bros.. Some of them add their own name to the disk jacket to indicate that the movie is not owned by the MCA. After Discovision Associates closed in early 1982, the Universal Studios video videodisc label, called MCA Videodisc until 1984, began republishing many DiscoVision titles. Unfortunately, quite a lot, like Battlestar Galactica and Jaws , is the time version of the original CAV or CLV Disco Vision version. Sometimes the re-compressed CLV problem Jaws no longer has the original soundtrack, has an incidental background music replaced for the video disc version due to licensing fees (music will not be available until THX LaserDisc box set was released in 1995). A Universal/Columbia joint production issued by the Disco MCA Vision in CAV and CLV versions, The Electric Horseman , is still not available in any other home video format with the original score intact; even the latest DVD releases have had substantial music substitutions from both instrumental scores and Willie Nelson's songs. The release of MCA Universal's Howard the Duck saw only the initial credit shown on the big screen before it was changed to 4: 3 for other movies. Over the years this was the only release of movie-based disks, until widescreen DVD format was released with extras. Also, release LaserDisc from E.T. The Extra-Terrestrial is the only format to include the Harrison Ford cut scenes that play the headmaster role that tells Elliott for letting the frogs free in a biology class.

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Comparison with other formats

VHS

LaserDisc has several advantages over VHS. It displays a much sharper image with a horizontal resolution of 425 TVL channels for NTSC and 440 TVL channels for PAL discs, while VHS only displays 240 TVL channels with NTSC. It can handle analog and digital audio where VHS is mostly just analog (VHS can have PCM audio in professional applications but not common), and NTSC discs can store multiple audio tracks. This allows an additional track such as director comments and other features to add to the movie, creating a special "Special Edition" release that is not possible with VHS. Disk access is random and chapter based, such as DVD format, which means that one can jump to a point on a given disk very quickly. For comparison, VHS will require boring and fast-forwarding rewinding to achieve certain points.

LaserDiscs are initially less expensive than video cassettes to produce, as they do not have moving parts and plastic outer shells required for VHS tapes to work, and the duplication process is much simpler. VHS tapes have at least 14 sections including actual bands while LaserDisc has one part with five or six layers. Disks can be removed in seconds while duplicate video recording requires a complex large ribbon duplication mechanism and is a time-consuming process. However, in the late 1980s, the average price of disk presses was more than $ 5.00 per double-sided disc, due to the large amount of plastic materials and expensive glassworking processes required to make metal stamper mechanisms. Due to the larger volume of demand, video cassettes quickly became cheaper to duplicate, for $ 1.00 in the early 1990s.

LaserDiscs has the potential to have a longer life than video cassettes. Since the discs are read optically and not magnetically, no physical contact needs to be made between the player and the disk, except for the clamp of players holding the disk at the center as it is spun and read. As a result, playback will not use a section containing information from the disc, and a properly made LD will theoretically last more than a lifetime. In contrast, the VHS tape holds all the image and sound information on the tape in the magnetic layer in contact with the head of the spinner on the head drum, causing progressive wear with every use (although later in VHS lifetime, technical improvements allowed the tapes to be created and played back without contact). The recording is also thin and smooth, and it's easy for player mechanisms, especially on low quality or broken models, to mis-manage the tape and damage it by shrinking it, frilling (edging) edges, or even breaking it.

DVD

At the time of the advent of DVD, LaserDisc has declined in popularity, so the two formats never directly compete with each other.

LaserDisc is a composite video format: luminance information (black and white) and chrominance (color) are transmitted in one signal, separated by the receiver. While a good comb filter can do enough, both of these signals can not be completely separated. On DVD, data is stored in the form of digital blocks that make up each frame independently. The resulting signal depends on the equipment used to master the disk. Signals range from composite and split, to YUV and RGB. Depending on which format to use, this can result in much higher fidelity, especially on strong color borders or high detail areas (especially if there is moderate movement in the picture) and low-contrast details such as skin color, where the comb filter is almost certain stain some details.

Unlike the full digital DVD, LaserDiscs only uses analog video. Because the LaserDisc format is not digitally encoded and does not use compression techniques, it is immune to video macroblocking (most noticeable as blockiness during high motion sequences) or contrasting appeal (lines look smooth in gradient areas, such as out-of-focus backgrounds, or light casts from spotlights) that can be caused by the MPEG-2 encoding process when the video is set up for DVD. Early DVD releases have the potential to surpass their LaserDisc counterparts, but are often managed just to match them to image quality, and in some cases, the LaserDisc version is preferred. However, man-aided encoders operated manually by specialists can greatly reduce the incidence of artifacts, depending on play time and image complexity. At the end of the LaserDisc working life, the DVD lives up to its potential as a superior format.

DVDs use compressed audio formats such as Dolby Digital and DTS for multichannel sound. Most LaserDiscs are encoded with stereo (often Dolby Surround) quality 16bit/44.1 kHz audio CD tracks as well as analog audio tracks.

DTS-encoded LaserDiscs has a DTS soundtrack of 1,235 kbit/s instead of reducing the bitrate of 768 kbit/s commonly used on DVDs with optional DTS audio.

Benefits

The LaserDisc player can provide a large degree of control over the playback process. Unlike many DVD players, the transport mechanism always obeys the user's commands: pause, fast-forward, and fast-reverse commands are always accepted (restrictions, of course, malfunctions). There is no "User Banning Option" where the content protection code instructs players to reject commands to skip certain sections (such as fast forwarding via copyright alerts). (Some DVD players, especially high-end units, have the ability to skip blocking code and play unlimited video, but this feature is not common in the ordinary consumer market.)

With CAV LaserDiscs, users can jump directly to each video frame by simply entering the frame number on the remote keypad, a feature that is not common among DVD players. Some DVD players have a cache feature that stores a number of videos in RAM that allow players to index DVDs as fast as LD, even down to frames across multiple players.

Damaged spots on LaserDisc can be rotated through or skipped, while DVDs often become unplayable through damage. Some newer DVD players feature improved skip algorithms, which reduce this problem by continuing to play the disc, filling in an unreadable area of ​​images with free space or frozen frames from the last readable image and sound. The success of this feature depends on the amount of damage. The LaserDisc player, while working in full analog, recovers from such errors faster than the DVD player. The direct comparison here is almost impossible due to the difference in the slim size between the two media. A 1 inch (3 cm) stroke on the DVD may cause more problems than a 1 inch (3 cm) streak on LaserDisc, but fingerprints that take 1% of DVD area will almost certainly cause fewer problems than similar marks covering 1% LaserDisc surface.

Similar to the debate of CD versus LP sound quality common in the audiophile community, some videophiles argue that LaserDisc retains the "smooth", more "like a movie", natural images while the DVD still looks a bit more artificial. Early DVD demo DVDs often had compression or encoding problems, providing additional support for such claims at the time. However, the video signal-to-noise ratio and LaserDisc bandwidth are substantially less than DVDs, making DVDs appear sharper and clearer for most viewers.

Another advantage, at least for some consumers, is the lack of anti-piracy technology. It was claimed that Macrovision copyguard protection could not be applied to LaserDisc, due to the design of the format. The vertical blanking interval, in which Macrovision signals will be applied, is also used for timing and/or frame code and player control codes on the LaserDisc player, so the test disk with Macrovision will not play at all. There has never been a push to redesign the format even though the potential for piracy is clear because of its relatively small market share. The industry just decided to assemble it into DVD specification.

LaserDisc support for multiple audio tracks allows for a large additional material to be included on disk and makes it the first format available for the "Special Edition" release; The 1984 Criteria Collection edition of Citizen Kane is generally credited as the first "Special Edition" release to home video, and to set the standard on which the future SE disk is measured. This disc provides interviews, comment tracks, documentaries, still photos, and other features for historians and collectors.

Losses

Despite the advantages over competing technologies at the time (ie VHS and Betamax), the format did have flaws. These heavy disks (weighing about 250 grams (half a pound) each), are impractical, more vulnerable than VHS tapes for damage if mismanaged, and manufacturers do not market LD units with recording capabilities to consumers. In addition, due to its size, greater mechanical effort is required to play the disc at the right speed, resulting in more noise generated than other media.

Analog video signals that take up space from a limited playback duration of LaserDisc up to 30/36 minutes (CAV NTSC/PAL) or 60/64 minutes (CLV NTSC/PAL) per side due to hardware manufacturer rejection to reduce number of rows for increased play time. Once one side has finished playing, the disc must be flipped to continue watching the movie, and some titles fill two or more discs. Many players, especially units built after the mid-1980s, can "flip" discs automatically by rotating the optical pickup to the other side of the disc, but this is accompanied by a pause in the film during side changes. If the film is longer than what can be stored on two sides of one disc, manually swapping to a second disc is required at some point during the movie. One exception to this rule is the Pioneer LD-W1, which features the ability to load two discs and play each side of one disc and then switch to playing each side of the other disc. In addition, perfectly silent frames and random access to individual silent frames are limited to the more expensive CAV disks, which only have 30 minutes of playback time per side. In subsequent years, Pioneer and other manufacturers overcame this limitation by including digital memory buffers, which "grabbed" a single field or frame from the CLV disk.

The analog information encoded in LaserDiscs does not include any form of checksum or error correction. Therefore, a bit of dust and scratches on the surface of the disc can cause read errors causing various video quality problems: interruptions, scratches, static bursts, or momentary image interruptions. In contrast, the digital MPEG-2 format information used on DVDs has a default error correction that ensures that signals from damaged disks will remain identical to the perfect disk to the point where damage to the disk surface is so important that it prevents the laser from being able to identify data that can used.

In addition, LaserDisc video sometimes shows a problem known as "crosstalk". This problem may arise when the laser optical pickup assembly in the player comes out of alignment or because the disk is damaged or too curved, but it can also happen even with well-functioning players and new factory-disks, depending on electricity and mechanics. alignment problems. In this case, the problem arises due to the fact that CLV requires subtle changes in rotating speed at various points during playback. During speed changes, the optical pickup inside the player may read the video information from a track adjacent to the intended one, causing data from two tracks to be "cross"; additional video information extracted from the second track appears as a distortion in an image that looks like a circling "barber pole" or a static rolling line.

Assuming the player's optical pickup is in the correct working order, crosstalk distortion usually does not occur during playback of CAV LaserDiscs format, since the rotation speed never varies. However, if the player calibration is damaged or if the CAV disc is damaged or damaged, other problems affecting tracking accuracy may occur. One of the problems is the "laser lock", in which the player reads the same two columns for the given frame over and over again, causing the image to look frozen as if the movie had stopped.

Another significant issue unique to LaserDisc is one that involves inconsistencies in playback quality between different players and player models. In most televisions, a given DVD player will produce images that are visually indistinguishable from other units. The difference in image quality between players only becomes noticeable on large televisions and a big leap in image quality is generally only obtained with expensive expensive players, allowing for post MPEG-2 stream processing during playback. In contrast, the quality of LaserDisc playback is highly dependent on the quality of the hardware. The main variations in image quality arise between the makers and models of different LD players, even when tested on medium-to-low grade televisions. The real benefits of using high quality equipment have helped keep demand for some high players, thus also keeping prices for units high enough. In the 1990s, renowned players sold for prices ranging from US $ 200 to over $ 1,000, while older and less desirable players can be purchased in working conditions for just $ 25.

Many early LDs are not produced properly; sometimes a substandard adhesive is used to unite the two sides of the disc. The adhesive contains impurities that are able to penetrate the lacquer seal layer and chemically attack the metalized reflective aluminum layer, causing it to oxidize and lose its reflective characteristics. This is a problem called "rotting lasers" among LD enthusiasts, also called "flash color" internally by the LaserDisc-pressing plant. Some form of rotted laser can appear as black spots that look like burning mushrooms or plastic that causes the disc to leap and film to indicate excessive spots. But, for the most part, rotten discs can actually perform fine with the naked eye.

Then the optical standard has been known to suffer from the same problem, including a large number of defective CDs manufactured by Philips-DuPont Optical at Blackburn facility, Lancashire in the UK during the late 1980s/early 1990s.

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Impact and decrease

LaserDisc does not have high market penetration in North America because of the high cost of players and discs, which are much more expensive than VHS players and cassettes, and because of the confusion of markets with low-tech CEDs, which also use the Videodisc name. While the format was not widely adopted by North American consumers, it was well received among videophiles because of superior audio and video quality compared to VHS and Betamax tapes, found a place in nearly a million American homes by the end of 1990. The format is more popular in Japan than in North America as prices remain low to ensure adoption, resulting in a minimal price difference between the higher-quality VHS tapes and LaserDiscs, helping ensure that it quickly becomes the dominant consumer video format in Japan. The anime collectors in each country that released the LD format, which includes North America and Japan, are also fast accustomed to this format, and are looking for higher quality LaserDisc video and sound and the availability of many titles that are not available in VHS. LaserDiscs is also a popular alternative to videotapes among movie aficionados in more affluent areas of Southeast Asia, such as Singapore, due to their high integration with Japanese export markets and superior long life of disc-based media compared to videocassettes, especially in humid air. the condition is endemic to that area in the world.

This format also became very popular in Hong Kong in the 1990s before the introduction of VCD and DVD; although people rarely buy discs (because each LD is priced around $ 100), high rental activity helps the video rental business in the city grow larger than ever. Due to integration with Japanese export markets, NTSC LaserDiscs is used in the Hong Kong market, in contrast to PAL standards used for broadcasts (this anomaly is also available for DVDs). This creates a market for multi-system TV and multi-VCR systems that can display or play both PAL and NTSC materials in addition to SECAM materials (which were never popular in Hong Kong). Some LD players can convert NTSC signals to PAL so most of the TVs used in Hong Kong can display LD materials.

Despite its relative popularity, manufacturers refuse to market LaserDisc devices that can be recorded in the consumer market, although competing VCR devices can record onto tapes, which harm worldwide sales. Uncomfortable disk size, high cost of both players and media and the inability to record to disk combined to take a serious toll on sales, and contribute to poor adoption rate format.

Although the LaserDisc format was replaced by DVDs in the late 1990s, many of LD's titles are still highly coveted by movie fans (eg, Disney's Song of the South which is not available in the US in any format but published in Japan on LD). This is mainly because there are many films that are still available in LD and many other LD releases containing additional material that is not available on the next DVD version of the films. By the end of 2001, many titles were released on VHS, LD and DVD in Japan.

LD players are also sometimes still found in contemporary physics and high school classrooms in North America, to play the Physics classic cinema discs in the mid-20th century. EncyclopÃÆ'Â|dia Britannica i> films that reproduce classical experiments in areas that are difficult or impossible to replicate in a laboratory in an educational setting. These films have now been released on DVD.

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Further developments and apps

Computer control

In the early 1980s, Philips produced a customized LaserDisc player model for the computer interface, dubbed "professional". In 1985, Jasmine Multimedia created a LaserDisc jukebox featuring music videos from Michael Jackson, Duran Duran, and Cyndi Lauper. When connected to a PC, this combination can be used to display images or information for educational or archival purposes, such as thousands of scanned scanned mediated texts. This strange device can be considered the earliest equivalent of a CD-ROM.

In the mid-1980s, Lucasfilm pioneered the non-linear EditDroid editing system for movies and television based on computer-controlled LaserDisc players. Instead of printing daily on film, the negatives processed from the day's shoot will be sent to master factories to be assembled from their 10-minute camera element into a 20-minute movie segment. These are then ridden to one-sided empty LaserDiscs, such as DVDs will be burned at home today, allowing for easier selection and preparation of edited decision lists (EDL). In the days before video aid was available in cinematography, this was the only other way for the film crew to see their work. EDL goes to the negative cutter which then cuts the negative camera and composes the finished film. Only 24 EditDroid systems have ever been created, although the idea and technology are still in use today. Then the EditDroid experiment borrowed from hard-drive technology has multiple discs on the same spindle and adds a lot of head playback and lots of electronics to the basic jukebox design so that every point on each disc will be accessible in seconds. This eliminates the need for shelves and shelves of LaserDisc industry players since the EditDroid disc is only one side.

In 1986, a SCSI-equipped LaserDisc player attached to a BBC Master computer was used for the BBC Domesday Project. The player is called LV-ROM (LaserVision Read Only Memory) as a disc containing driving software as well as video frames. The disk uses the CAV format, and the data is encoded as a binary signal indicated by analog audio recording. This disk can contain in any CAV video/audio or video/binary data frame, but not both. The "Data" frame will appear empty when played as a video. It's typical for each disk to start with a catalog of disks (some empty frames) then video introduction before the rest of the data. Because the format (based on the hard disk ADFS format) uses the initial sector for each file, the data layout effectively skips over any video frames. If all 54,000 frames are used for data storage, LV-ROM disks can contain 324 MB of data per side. The Domesday Project System also includes genlock, enabling video frames, clips and audio to be mixed with graphs originating from the BBC Master; this is used for a great effect to display high resolution photos and maps, which can then be enlarged.

During the 1980s in the United States, Digital Equipment Corporation developed independent IVIS (Interactive VideoDisc Information System) PC control for training and education. One of the most influential programs developed at DEC is Decision Point, a management game simulation, which won the Nebraska Video Disc Award for Best of Show in 1985.

The HyperCard scripting language from Apple provides Macintosh computer users with the means to design a slide, animation, video and sound database from LaserDiscs and then create an interface for users to play certain content from the disk through software called LaserStacks. The user-generated "stacks" are very popular in education where teacher-generated stacks are used to access discs ranging from art collections to basic biological processes. Commercially available stacks are also popular in Voyager companies that may be the most successful distributors.

Commodore International's 1992 multimedia presentation system for Amiga, AmigaVision, includes device drivers for controlling multiple LaserDisc players via serial ports. Paired with Amiga's ability to use Genlock, this allows the LaserDisc video to be overlaid with computer graphics and integrated into multimedia presentations and displays, many years before such a practice is commonplace.

Pioneer also makes computer-controlled units like the LD-V2000. It has a RS-232 back-panel serial connection via a five pin DIN connector, and no front panel controls except Open/Close . (The disc will play automatically during insertion.)

Under a contract from the US military, Matrox produces a combination computer/LaserDisc player for instructional purposes. The computer is 286, the LaserDisc player is only capable of reading analog audio tracks. Together they weigh  £ 43 (20 kg) and a firm grip is given if two people are asked to lift the unit. The computer controls the player through the 25-pin serial port on the back of the player and the ribbon cable connected to the proprietary port on the motherboard. Many of these were sold as surplus by the military during the 1990s, often without controlling software. However, it is possible to control the unit by removing the ribbon cable and connecting the serial cable directly from the computer serial port to the port on the LaserDisc player.

Computer game

The instant access capability of this format allows for a new generation of LaserDisc-based video game arcade and several companies see the potential in using LaserDiscs for video games in the 1980s and 1990s, starting in 1983 with Sega's Astron Belt . American Laser Games and Cinematronics produce complex arcade consoles that use random access features to create interactive movies like Dragon's Lair and Ace Space . Similarly, Laseractive Pioneer and Halcyon were introduced as home video game consoles using LaserDisc media for their software.

MUSE LD

In 1991, several manufacturers announced the specification for what would be known as MUSE LaserDisc, representing a range of nearly 15 years to the achievement of the HD analog optical disc system will eventually be duplicated digitally by HD DVD and Blu-ray Disc. Encoded using the Hi-Vision NHK analog "MUSE" TV system, the MUSE disk will operate like a standard LaserDiscs but will contain 1,125-line high-definition (1,035rata seen) video (Sony HDVS) with an aspect ratio of 5: 3. MUSE players is also capable of playing standard NTSC disc formats and is superior in performance to non-MUSE players even with these NTSC discs. Players with MUSE have some important advantages over standard LaserDisc players, including red lasers with wavelengths that are much narrower than lasers found in standard players. The red laser is capable of reading disc defects such as scratches and even light rod decay that will cause most other players to stop, stutter or break up. Crosstalk is not a problem with MUSE disks, and narrow laser wavelengths allow for the removal of virtual crosstalk with normal discs.

To view MUSE-encoded discs, it is necessary to have a MUSE decoder other than a compatible player. There is a television with a MUSE decoding already in it and a set top tuner with a decoder that can provide the right MUSE input. The price of equipment is high, especially for early HDTVs that generally surpass US $ 10,000, and even in Japan the market for MUSE is very small. Players and disks have never been officially sold in North America, although some distributors import MUSE discs along with other import titles. Terminator 2: Judgment Day , Lawrence of Arabia , Own League , Bugsy , Close Encounters of the Third Kind , Bram Stoker Dracula and Chaplin is one of the theatrical releases available on MUSE LDs. Several documentary films, including one on Formula One in Suzuka Circuit Japan were also released.

Image discs

The image disc has an artistic etching on one side of the disc to make the disc more visually appealing than the standard glossy silver surface. This etching may look like a movie character, logo, or other promotional material. Sometimes the LD side is made with colored plastic, rather than the obvious material used for the data side. LDs image disks only have video material on one side because the "image" side can not contain any data. Rare picture discs in North America.

LD-G

Pioneer Electronics - one of the largest proponents of the format/investor - is also deeply involved in the karaoke business in Japan, and uses LaserDiscs as a storage medium for music and additional content such as graphics. This format is generally called LD-G. While some other karaoke labels are produced LaserDiscs, there is nothing like the extent of competition in the industry that exists today, as almost all manufacturers have switched to CD G discs.

Anamorphic LaserDiscs

With the release of 16: 9 televisions in the early 1990s, Pioneer and Toshiba decided it was time to take advantage of this aspect ratio. Squeeze LDs enhanced 16: 9-widescreen ratio LaserDiscs. During the video transfer phase, the film is stored in anamorphic "squeezed" format. Widescreen movie images are stretched to fill entire video frames with less or no wasted video resolution to create letterbox blades. The advantage is a 33% larger vertical resolution compared to the LaserDisc widescreen letterbox. This same procedure is used for anamorphic DVDs, but unlike all DVD players, very few LD players have the ability to not save images for 4: 3 sets, If the discs are played on a standard 4: 3 television, the image will be distorted. However some 4: 3 sets (such as Sony WEGA series) can be set to cancel the blackmail picture. Since very few people outside of Japan have 16: 9 screens, the selling power of this particular disc is very limited.

No LaserDisc anamorphic titles are available in the US except for promotional purposes. After the purchase of television viewers Toshiba 16: 9 has the option of selecting Warner Bros. 16: 9. The title includes Not Up , Old Strong , Fugitive , and Free Willy . The range of Japanese titles is different. The series of releases under the Pioneer "Squeeze LD" banner of most of Carolco's titles include Basic Instances Stargate , Terminator 2: Judgment Day , < i> Showgirls , Cutthroat Island , and Cliffhanger . Terminator 2 was released twice in Squeeze LD, the second release of THX certification and a significant increase from the first.

Recordable format

Other types of video media, CRVdisc , or "Recordable Video Disc Components" are available for a short time, mostly for professionals. Developed by Sony, CRVdiscs resemble early PC CD-ROM caddies with discs inside resembling full-sized LDs. CRVdiscs are blank, write-once, read-many media that can be recorded once on each side. CRVdiscs are used mostly for backup storage in professional and commercial applications.

Another form of recordable LaserDisc that is fully compatible with playback with the LaserDisc format (unlike CRVdisc with caddy enclosure) is RLV , or Recordable Laser Videodisc . It was developed and first marketed by Optical Disc Corporation (ODC, now ODC Nimbus) in 1984. Disk RLV, like CRVdisc, is also a WORM technology, and works exactly like a CD-R disc. The RLV disk looks almost exactly like the standard LaserDiscs, and can be played in the standard LaserDisc player player after being recorded.

The only cosmetic difference between the RLV disk and LaserDiscs paired by the manufacturer is the reflective violet (or blue with some color RLV) colors generated from the dye embedded in the reflective layer of the disk to make it recording, as opposed to the silver mirror appearance of Regular LDs. The purplish color of RLVs is very similar to DVD-R and DVD R discs. RLV is very popular for making short-term LaserDiscs counts for specialized apps such as interactive kiosks and flight simulators.

Pioneer also produces a rewritable LaserDisc system, VDR-V1000 "LaserRecorder" whose discs are claimed to have erased/recorded potential 1,000,000 cycles.

This recoverable LD system has never been marketed to the general public, and is poorly known for creating misconceptions that home recording for LaserDiscs is unlikely and the "weakness" of the LaserDisc format.

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LaserDisc size

The most common LaserDisc sizes are 30 cm (11.8 inches), approximately the size of the LPs (30.5 cm). This disc allows for 30/36 minutes per side (CAV NTSC/PAL) or 60/64Ã, per side (CLV NTSC/PAL). Most of the programming for the LaserDisc format is produced on this disc.

A number of LaserDiscs measuring 20 cm (7.9 inches) were also published. This smaller "EP" -sized LD allows 20 minutes per side (CLV). They are much less prevalent than the full size of LD, especially in North America, and approximate 45rpm (7 inches (17.8 cm) size of single vinyl. This disk is often used for compilation of music videos (eg "Breakout" Bon Jovi, "Bananarama's Video Singles" or T'Pau's "View From a Bridge".)

There is also a 12 cm (4.7 inch) (CD size) "single" -style disc produced that can be played on a LaserDisc player. These are referred to as Video CD (CD-V) discs, and Video Single Discs (VSD). CD-V carries up to five minutes of LaserDisc analog video content (usually music videos), as well as up to 20 minutes of digital CD track audio. The original 1989 release of the retrospective David Bowie Sound Vision CD box set out clearly featured the "Ashes to Ashes" CD-V video, and standalone CD-V promo featuring video, plus three audio tracks: "John, I'm Only Dancing "," Changes ", and" The Supermen ".

CD-V does not get confused with Video CD (all of which are digital and can only be played on VCD players, DVD players, CD-i players, computers, and later-model LaserDisc players that can also play DVDs, such as the Pioneer DVL-9xx series ). CD-V can only be played on a LaserDisc player with CD-V capability. VSD is same as CD-V, but without audio CD track. CD-V was rather popular for a short time around the world, but soon faded from view. VSD is only popular in Japan and other parts of Asia, and has never been fully introduced to the world.

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See also

• Blu-ray
• CED
• SelectaVision
• VHD
• Videodisc

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References

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Further reading

• Jordan Isailovic, Videodisc and Optical Memory System . Vol. 1, Boston: Prentice Hall, 1984. ISBNÃ, 978-0-13-942053-5
• Lenk, John D. Full Guide for Laser/VideoDisc Player Troubleshooting and Repair . Englewood Cliffs, N.J.: Prentice-Hall, 1985. ISBNÃ, 0-13-160813-4.

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External links

• UK LaserDisc Player Archive: including North American players
• LaserDisc Database: title database, profile, marketplace
• VCR 'Total Rewind' Museum, including LaserDisc and other vintage formats
• Available spectrum organizations
• The addition of digital sound, by Kees Schouhamer Immink
• "World On A Silver Platter: A Short History of Optical Discs"
• BLAM entry page for discovision
• LaserDisc FAQ, (original source)
• DiscoVision MCA History via Wayback Machine
• BLAM Entertainment Group: includes Star Wars and Star Trek LaserDisc catalogs and a list of Dolby Digital and DTS titles with
• Blog and Database: article, title information, marketplace
• RCA SelectaVision VideoDisc FAQ: also contains some history DiscoVision
• UK eBay Guides - Laser PlayersDisc and Laserdiscs - Formats and Features
• Guides and software for Matrox 286/LaserDisc player

Source of the article : Wikipedia